The present invention relates to a fuel injection control for internal combustion engine.
As a conventional fuel injection control for internal combustion engine, the so-called "multi-point system" in which a fuel injector is provided for each cylinder is generally used and the fuel injectors for respective cylinders are actuated according to predetermined crank angles to inject fuel sequentially is generally used. This system makes it possible to make a width range of pulse for driving the injectors wide and to thereby facilitate an air-fuel ratio control.
In such conventional system, however, the width of pulse for driving the injectors for, for example, a 4-cycle, 2-liter engine, may be around 15 m sec at a heavy load under a complete idling condition and around 200 m sec during a starting period of the engine at a very low temperature. Therefore, a large dynamic range of drive time is required and a control device for controlling such large dynamic range must have a complicated and expensive construction due to the fact that a timer thereof must have a large number of bits, etc.